package com.example.administrator.yuejian35.Login.activity;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;

import com.example.administrator.yuejian35.Login.GuidePageAdapter;
import com.example.administrator.yuejian35.MainActivity;
import com.example.administrator.yuejian35.R;

import java.util.ArrayList;
import java.util.List;

/**
  * 实现首次启动的引导页面
  */
public class GuideActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener{
    private ViewPager vp;
    private int []imageIdArray;//图片资源的数组
    private List<View> viewList;//图片资源的集合
    private ViewGroup vg;//放置圆点

            //实例化原点View
            private ImageView iv_point;
    private ImageView[]ivPointArray;

            //最后一页的按钮
            private Button ib_start;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
       setContentView(R.layout.activity_guide);

        ib_start = (Button) findViewById(R.id.guide_ib_start);
        ib_start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(GuideActivity.this,MainActivity.class));
                finish();
                }
            });

        //加载ViewPager
        initViewPager();

        //加载底部圆点
        initPoint();
        }
 /**
          * 加载底部圆点
          */
            private void initPoint() {
   //这里实例化LinearLayout
        vg = (ViewGroup) findViewById(R.id.guide_ll_point);
        //根据ViewPager的item数量实例化数组
        ivPointArray = new ImageView[viewList.size()];
        //循环新建底部圆点ImageView，将生成的ImageView保存到数组中
        int size = viewList.size();
        for (int i = 0;i<size;i++){
            iv_point = new ImageView(this);
          iv_point.setLayoutParams(new ViewGroup.LayoutParams(20,20));
            iv_point.setPadding(50,30,50,30);//left,top,right,bottom
            ivPointArray[i] = iv_point;
            //第一个页面需要设置为选中状态，这里采用两张不同的图片
          if (i == 0){
                iv_point.setBackgroundResource(R.drawable.ic_full);
                }else{
                iv_point.setBackgroundResource(R.drawable.ic_empty);
                }
           vg.addView(ivPointArray[i]);
            }
        }
    /**
          * 加载图片ViewPager
          */
            private void initViewPager() {
     vp = (ViewPager) findViewById(R.id.guide_vp);
        //实例化图片资源
    imageIdArray = new int[]{R.drawable.guide1, R.drawable.guide2, R.drawable.guide3};
       viewList = new ArrayList<>();
     //获取一个Layout参数，设置为全屏
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);

      //循环创建View并加入到集合中
        int len = imageIdArray.length;
        for (int i = 0;i<len;i++){
            //new ImageView并设置全屏和图片资源
            ImageView imageView = new ImageView(this);
            imageView.setLayoutParams(params);
   imageView.setBackgroundResource(imageIdArray[i]);
           //将ImageView加入到集合中
         viewList.add(imageView);
           }

       //View集合初始化好后，设置Adapter
      vp.setAdapter(new GuidePageAdapter(viewList));
        //设置滑动监听
        vp.setOnPageChangeListener(this);
       }
  @Override
   public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        }
    /**
          * 滑动后的监听
          * @param position
          */
          @Override
public void onPageSelected(int position) {
        //循环设置当前页的标记图
        int length = imageIdArray.length;
       for (int i = 0;i<length;i++){
            ivPointArray[position].setBackgroundResource(R.drawable.ic_full);
            if (position != i){
                ivPointArray[i].setBackgroundResource(R.drawable.ic_empty);
                }
            }
     //判断是否是最后一页，若是则显示按钮
        if (position == imageIdArray.length - 1){
           ib_start.setVisibility(View.VISIBLE);
           }else {
          ib_start.setVisibility(View.GONE);
           }
   }
   @Override
   public void onPageScrollStateChanged(int state) {
        }
}
